From the sixteenth century onward, artistic and geometric drawing were powerfully stimulated by the development of new instruments for visual representation. For drawing from real life, the Renaissance has left us a variety of perspective instruments whose applications included portraiture, drawing objects and geometric bodies, statues and landscapes, and designing fortresses. Through their evolution into the camera obscura and camera lucida, these instruments foreshadowed the birth of photography. In the eighteenth century, complicated mechanisms were designed to produce special optical illusions, such as anamorphoses. These distorted images had to be viewed at an angle or reflected on conical and cylindrical mirrors in order to be restored to proper proportions. For geometric drawing, architects had a wide range of instruments, redesigned and perfected until the nineteenth century: precision compasses with drawing pens and micrometer screw, rod compasses for large circumferences, ellipsographs, reduction compasses for drawing polygons, eidographs and pantographs for reproducing drawings, double rulers and T-squares for drawing parallel lines, and folding squares and goniometers for plotting various types of angles in fortress plans.